On 05/02/2011 11:50 AM, Marc Lavallée wrote: > Mon, 02 May 2011 06:59:40 +0200, > Jörn Nettingsmeier <[email protected]> wrote : > >> not native, but here's a very simple one that has been shoehorned >> into a third-order workstation: >> http://cec.concordia.ca/econtact/11_3/nettingsmeier_ambisonics.html > > I'd like to understand the "Versatile (and Quite Luxurious) Speaker > Setup" part of your article, and how it relates to your recommendation > on the number of speakers:
first of all, this example was picked more or less out of thin air in order to show that there are really no limits on the type of layout, as long as it's more or less regular. it's no standard, and i must confess i have never mixed on exactly this setup (although i created a similar setup once, for a temporary installation). >> in production, use HOA. in reproduction, use as many speakers >> as you can afford, up to a limit determined by the order of the >> source material: >> 1st OA: no more than six >> 2nd OA: six or eight >> 3rd OA: eight, twelve if necessary >> >> it's now an established fact that too many speakers degrade >> the result for any given order. > > Is your "versatile" setup appropriate for 1st, 2nd and 3rd OA? if you can afford eight speakers on the horizontal plane, you get some kind of native 5.1 that is not totally wrong, certainly no worse than what you find in most homes (if you find 5.1 at all). and you can do native quad, you can do first order over four speakers, and first, second and third over all eight. lots of opportunities for a/b comparison. when i mix, i always run several decoders in parallel, with subsets of my maximum setup, to see how the mix degrades. so i work in third order (if i can - my home setup only does 2nd), but i will frequently fall back to first order on all speakers or just a subset, or even UHJ stereo - my goal is to find a middle ground that delivers good UHJ stereo to my customer and also retains ambisonic goodness for the future. so yes, i do care how it sounds in first order. but it's like a mono compatibility check, not like it's my primary target. almost all recordings i do, i think in surround and fold down to stereo, even if it is clear that the customer won't ever care for surround at all. only in cases of emergency will i use stereo-specific tweaks. > Does the elevated hexagon work with FOA, or is it only for HOA? > Is the octagon good for FOA, even if you don't seem to recommend it? > Finally: is it a good setup for domestic listening? this setup is very likely overdone for first-order. i haven't explored first-order periphonic much, but i swear by the regular hexagon for first-order horizontal (and it's also very nice for second order). in my experience, first-order horizontal over eight speakers is slightly but noticeably worse in the sweet spot than six, so not recommended for homes if you seldom if ever listen to third order material. for larger audiences, the game seems to be a bit different, although i don't quite understand why. i find 1st order over eight speakers covers a larger area more easily and uniformly than six, but the theory says it shouldn't, because outside the sweet spot, rV reconstruction is mostly not happening and everything relies on rE, which is degraded by using more speakers than necessary... if i were to build a periphonic rig at home (which i might, when i have the spare cash), it would be three on the floor, six at ear height, three on the ceiling, i.e. a slanted dodecahedron. should be good for second order periphonic, still small enough to be able to enjoy native soundfield recordings without ruining the rE too much, and no compromise for horizontal-only material. if you're not interested in sounds from below the equator (which means you'll miss all those exciting footsteps and running water sounds), you could try a hemisphere with eight and four and maybe an added zenith (or just six and three), but then you need some spherical harmonic alphageek to compute a decoder for you that doesn't pull upwards like crazy. i'm trying to learn how to do it, but i'm only beginning to understand the problem, nowhere near to getting it done myself. many people swear by stacked rings, and i can say that the one time i've had the chance to work on three rings-of-eight, i was amazed to find no noticeable phasing issues, even though the room was almost dead (rt60 of 0.3s down to at least 150hz, the lovely SPIRAL rig in huddersfield). stacked rings still feel a bit wasteful to me, and they have these holes at the bottom and up top (where the SPIRAL has recently added a zenith speaker), but the absence of phasing was quite striking. i have too little experience with rings to conjecture a general rule from this, but i'm looking forward to my next stacked ring setup... -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister (VDT) http://stackingdwarves.net _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
